1. Field of the Invention
The present invention relates to an apparatus for and method of processing image data, and more particularly, to an apparatus for and method of processing image data by sub-sampling image data.
2. Description of the Related Art
Generally, apparatuses for processing a digital image by using image data processing technology may use image recognizing sensors, and may be, for example, digital cameras, personal digital assistants (PDAs), phone cameras, or personal computer (PC) cameras.
An apparatus for processing a digital image may generate an image file by processing an image captured via an image pickup device by using a digital signal processor and compressing the processed image, and may store the generated image file in a memory.
Also, the apparatus may display an image from an image file, captured via the image pickup device or stored in a storage medium, on a display device such as a liquid crystal display (LCD).
Regarding such an apparatus, competition between manufacturers has led to developments in high sensitivity photographing, since competition in developing high pixel photographing is saturated. Here, noise due to heat generated by a charge coupled device (CCD) or by a complementary metal oxide semiconductor (CMOS) or low frequency noise due to interference in an electronic circuit is amplified while amplifying a signal during high sensitivity photographing. Accordingly, it is required to effectively remove noise that may occur on an output image.
Conventionally, a low pass filter (LPF) is widely used for noise reduction (NR). Since a noise component is typically generated as a high frequency component on a plane of an image, a LPF blocks the high frequency component so as to remove the noise component.
However, a LPF removes an edge component of an image, and thus image sharpness decreases. Accordingly, technology relating to removing noise while maintaining an edge component is required.
Consequently, technology relating to removing noise by sampling an image and processing the image by using software is introduced.
However, processing speeds of such conventional technology using software are slow. In other words, all operations are performed in a central processing unit (CPU), and thus the processing speed depends on the CPU. Since a CPU not only processes an image but also performs other operations simultaneously, the processing speed is limited. Also, image data before being processed in software is stored in a storage device, such as a SecureDigital/CompactFlash/SmartMedia (SD/CF/SM) card, and thus the speed at which image data is read is greatly limited.
Specifically, technology related to removing noise randomly accesses a storage device storing image data, while reading a data value for sub-sampling so as to process an image. In this case, a memory load is discontinuously generated, and thus the apparatus may be overloaded. Accordingly, the processing speed is decreased.